Slapping on a 5-string

I have a problem with slapping/popping on my 5-string. I am not able to slap the E and pop the D with ease/as fast as A to G. I was wondering if anyone else had/has this problem and any solutions would be great.

just turn on the metronome, and go though the patterns, slap on e and pop on d, and do it till you can do it in your sleep
slap-pop, slap-pop, get that clean and fast,

then, slap-slap-pop, triplets and sixteenths

then, slap-pop-pop, triplets and sixteenth notes

then, slap-slap-pop-pop in sixteenth notes,

then, practice doing one bar on the e and d, and then switch to the a and g with out stopping your groove, and try to get the transition clean, and get the slapping and popping on the e and d to sound as much like your popping on the a and g, you can practice this having the notes speak or all ghost notes too, whatever you want,
The whole time, you gotta remember to keep that b string silent, keep in mind to not hit it with your thumb, and try to mute with your fretting hand, by curling your thumb around or with your fingers,
And i just realized i need to practice this e and d slapping, I hope that helps

Hmm thats kinda odd to me, i had more trouble slapping the A string and poping the G string than I did from slapping the E and popping the D. What kind of bass do you have? the string spacing may have something to do with it. If its too tight you may hit the other strings while slapping and if its too wide your hands may not be able to do the stretch. But as they say practice will make perfect so just keep practicing and youll get it